OBJECTIVE: A high extracellular water (ECW) to intracellular water (ICW) ratio of skeletal muscle as assessed by bioelectrical impedance analysis is reportedly associated with loss of muscle strength. However, the validity of this index for heart failure (HF), which is likely associated with changes in the water distribution, is unclear.
RESULTS: This study involved 190 patients with HF. The total ECW and ICW of both upper and lower extremities were measured, and a high ECW/ICW ratio was defined as an ECW/ICW ratio higher than the median (≥0.636 for men, ≥0.652 for women). Low muscle strength was defined as reduced handgrip strength according to the criteria established by the Asian Working Group for Sarcopenia. Patients with a high ECW/ICW ratio had a lower handgrip strength (21.1 ± 8.1 kg vs. 27.6 ± 9.3 kg, P ≤ 0.05) and 6 min walk distance (329 ± 116 m vs. 440 ± 114 m) than those with a low ECW/ICW ratio. An increasing ECW and/or decreasing ICW was associated with a higher ECW/ICW ratio and a lower handgrip strength (P < 0.05). In the multivariate logistic regression analysis, a high ECW/ICW ratio and low skeletal muscle mass were independently associated with low muscle strength (P < 0.05).
CONCLUSIONS: A high ECW/ICW ratio in limb muscles, that is, the water imbalance of increasing ECW and/or decreasing ICW, is useful in assessing muscle quality in patients with HF.

We previously reported that sodium-glucose cotransporter 2 (SGLT2) inhibitors exert sustained fluid homeostatic actions through compensatory increases in osmotic diuresis-induced vasopressin secretion and fluid intake. However, SGLT2 inhibitors alone do not produce durable amelioration of fluid retention. In this study, we examined the comparative effects of the SGLT2 inhibitor dapagliflozin (SGLT2i group, n = 53) and the combined use of dapagliflozin and conventional diuretics, including loop diuretics and/or thiazides (SGLT2i + diuretic group, n = 23), on serum copeptin, a stable, sensitive, and simple surrogate marker of vasopressin release and body fluid status. After six months of treatment, the change in copeptin was significantly lower in the SGLT2i + diuretic group than in the SGLT2i group (-1.4 ± 31.5% vs. 31.5 ± 56.3%, p = 0.0153). The change in the estimated plasma volume calculated using the Strauss formula was not significantly different between the two groups. Contrastingly, changes in interstitial fluid, extracellular water, intracellular water, and total body water were significantly lower in the SGLT2i + diuretic group than in the SGLT2i group. Changes in renin, aldosterone, and absolute epinephrine levels were not significantly different between the two groups. In conclusion, the combined use of the SGLT2 inhibitor dapagliflozin and conventional diuretics inhibited the increase in copeptin levels and remarkably ameliorated fluid retention without excessively reducing plasma volume and activating the renin-angiotensin-aldosterone and sympathetic nervous systems.

UNASSIGNED: High sodium intake and fluid overhydration are common factors of and strongly associated with adverse outcomes in chronic kidney disease (CKD) patients. Yet, their effects on cardiac dysfunction remain unclear.
UNASSIGNED: The study aimed to explore the impact of salt and volume overload on cardiac alterations in non-dialysis CKD.
UNASSIGNED: In all, 409 patients with CKD stages 1-4 (G1-G4) were enrolled. Daily salt intake (DSI) was estimated by 24-h urinary sodium excretion. Volume status was evaluated by the ratio of extracellular water (ECW) to total body water (TBW) measured by body composition monitor. Recruited patients were categorized into four groups according to DSI (6 g/day) and median ECW/TBW (0.439). Echocardiographic and body composition parameters and clinical indicators were compared. Associations between echocardiographic findings and basic characteristics were performed by Spearman\'s correlations. Univariate and multivariate binary logistic regression analysis were used to determine the associations between DSI and ECW/TBW in the study groups and the incidence of left ventricular hypertrophy (LVH) and elevated left ventricular filling pressure (ELVFP). In addition, the subgroup effects of DSI and ECW/TBW on cardiac abnormalities were estimated using Cox regression.
UNASSIGNED: Of the enrolled patients with CKD, the median urinary protein was 0.94 (0.28-3.14) g/d and estimated glomerular filtration rate (eGFR) was 92.05 (IQR: 64.52-110.99) mL/min/1.73 m2. The distributions of CKD stages G1-G4 in the four groups was significantly different (p = 0.020). Furthermore, compared to group 1 (low DSI and low ECW/TBW), group 4 (high DSI and high ECW/TBW) showed a 2.396-fold (95%CI: 1.171-4.902; p = 0.017) excess risk of LVH and/or ELVFP incidence after adjusting for important CKD and cardiovascular disease risk factors. Moreover, combined with eGFR, DSI and ECW/TBW could identify patients with higher cardiac dysfunction risk estimates with an AUC of 0.704 (sensitivity: 75.2%, specificity: 61.0%). The specificity increased to 85.7% in those with nephrotic proteinuria (AUC = 0.713). The magnitude of these associations was consistent across subgroups analyses.
UNASSIGNED: The combination of high DSI (>6 g/d) and high ECW/TBW (>0.439) independently predicted a greater risk of LVH or ELVFP incidence in non-dialysis CKD patients. Moreover, the inclusion of eGFR and proteinuria improved the risk stratification ability of DSI and ECW/TBW in cardiac impairments in CKD.

BACKGROUND: Hemodialysis patient groups have advocated reducing dialysis fatigue and symptoms. We investigated whether compartmental fluid shifts were associated with peri-dialytic fatigue and symptoms.
METHODS: Sessional dialysis records of patients reporting both a short and delayed recovery (<1 h and ≥1 h) with corresponding bioimpedance measurements were reviewed.
RESULTS: One hundred and twenty-four patients reported both short and delayed recovery times, mean age 66.0 ± 14.8 years, 66.1% male. Differences between sessions included higher distress thermometer [4 (1-6) vs. 3 (0-5)], fatigue [4 (0-9) vs. 2 (0-7)], total symptom scores [20.5 (12.3-34.5) vs. 16 (7-28)], change in extracellular water to total body water ratios between body compartments [right leg/left arm 2.36 (1.23-4.19) vs. 1.28 (0.12-2.01), all p < 0.01] with delayed recovery, and more hemodialysis than hemodiafiltration sessions (χ2 4.6, p = 0.02).
CONCLUSIONS: Sessions with prolonged recovery times were associated with more peri-dialytic symptoms, psychological distress, and hemodialysis mode, and greater changes in compartmental fluid shifts.

BACKGROUND: Our aim was to develop and evaluate a method for the measurement of muscle mass during the 12-channel electrocardiogram (ECG), to determine the incidence of sarcopenia in patients with overhydration and to correct it for congestion.
METHODS: A 12-channel ECG that simultaneously provided multifrequency segmental impedance data was used to measure total body water (TBW), extracellular water (ECW), ECW/TBW ratio and appendicular muscle mass (AppMM), validated by whole-body dual-energy X-ray absorptiometry. The mean ECW/TBW ratio was 0.24 ± 0.018 (SD) and 0.25 ± 0.016 for young (age range 20-25 years) healthy males (n = 77) and females (n = 88), respectively. The deviation of the ECW/TBW ratio from this mean was used to correct AppMM for excess ECW (\'dry AppMM\') in 869 healthy controls and in 765 patients with chronic heart failure (CHF) New York Heart Association classes II-IV. The association of AppMM and dry AppMM with grip strength was also examined in 443 controls and patients.
RESULTS: With increasing N-terminal pro-brain natriuretic peptide (NT-proBNP), a continuous decline of AppMM indices is observed, which is more pronounced for dry AppMM indices (for males with NT-proBNP < 125 pg/mL: AppMM index mean = 8.4 ± 1.05, AppMM index dry mean = 8.0 ± 1.46 [n = 201, P < 0.001]; for females with NT-proBNP < 150 pg/mL: AppMM index mean = 6.4 ± 1.0, AppMM index dry mean = 5.8 ± 1.18 [n = 198, P < 0.001]; for males with NT-proBNP > 1000 pg/mL: AppMM index mean = 7.6 ± 0.98, AppMM index dry mean = 6.2 ± 1.11 [n = 137, P < 0.001]; and for females with NT-proBNP > 1000 pg/mL: AppMM index mean = 5.9 ± 0.96, AppMM index dry mean = 4.8 ± 0.94 [n = 109, P < 0.001]). The correlation between AppMM and upper-body AppMM and grip strength (r-value) increased from 0.79 to 0.83 (P < 0.001) and from 0.80 to 0.84 (P < 0.001), respectively, after correction (n = 443). The decline of AppMM with age after correction for ECW is much steeper than appreciated, especially in males: In patients with CHF and sarcopenia, the incidence of sarcopenia may be up to 30% higher after correction for ECW excess according to the European (62% vs. 57%, for males, and 43% vs. 31%, for females) and Foundation for the National Institutes of Health (FNIH) (56% vs. 46%, for males, and 54% vs. 38%, for females) consensus guidelines.
CONCLUSIONS: The incidence of sarcopenia in CHF as defined by the European Working Group on Sarcopenia and FNIH consensus may be up to 30% higher after correction for ECW excess. This correction improves the correlation between muscle mass and strength. The presented technology will facilitate, on a large scale, screening for sarcopenia, help identify mechanisms and improve understanding of clinical outcomes.

OBJECTIVE: To compare bioelectrical impedance analysis (BIA)-derived parameters in healthy volunteers and critically ill patients and to assess its prognostic value in an ICU patient cohort.
METHODS: Retrospective, observational data analysis.
METHODS: Single centre, tertiary-level ICU (Ziekenhuis Netwerk Antwerpen, ZNA Stuivenberg Hospital).
METHODS: 101 patients and 101 healthy subjects, participants of International Fluid Academy Days.
RESULTS: Compared to healthy volunteers, both male and female ICU patients had significantly higher values for total body water (TBW), extracellular water (ECW), extracellular fluid (ECF), plasma, and interstitial fluid volumes. The phase angle was significantly lower and the malnutrition index was significantly higher in ICU patients, regardless of gender. Non-survivors in the ICU had significantly higher extracellular water content (ECW, 50.7 ± 5.1 vs. 48.9 ± 4.3%, p = 0.047) and accordingly significantly lower intracellular water (ICW, 49.2 ± 5.1 vs. 51.1 ± 4.3%, p = 0.047). The malnutrition index was also significantly higher in non-survivors compared to survivors (0.94 ± 0.17 vs. 0.87 ± 0.16, p = 0.048), as was the capillary leak index (ECW/ICW).
CONCLUSIONS: Compared to healthy volunteers, this study observed a higher malnutrition index and TBW in ICU patients with an accumulation of fluids in the extracellular compartment. ICU non-survivors showed similar results, indicating that ICU patients and a fortiori non-survivors are generally overhydrated, with increased TBW and ECW, and more undernourished, as indicated by a higher malnutrition index.

UNASSIGNED: Total body water (TBW) fraction, which accounts for 60% of body weight, is an important indicator of body composition, and the extracellular water to TBW ratio (ECW/TBW) is reportedly useful in predicting clinical outcomes of patients with organ disorders. We aimed to clarify the clinical impact of preoperative ECW/TBW status on survival outcomes in cancer patients.
UNASSIGNED: We used a database of 320 colorectal cancer (CRC) patients who underwent potentially curative resections. Preoperative ECW/TBW was measured using a bioelectrical impedance analysis (BIA), and its correlation with patient survival outcomes, clinicopathological factors, laboratory data, and comorbidities were analyzed.
UNASSIGNED: A high preoperative ECW/TBW was significantly associated with poorer relapse-free survival (RFS; p = 0.001) and overall survival (OS; p = 0.003). A high ECW/TBW ratio was significantly associated with older age (p < 0.001), low BMI (p = 0.009), and right-sided tumors (p = 0.03). In a multivariate analysis, a high ECW/TBW significantly predicted a higher RFS mortality (HR: 2.07, 95% CI: 1.10-3.88, p = 0.024) and OS mortality (HR: 3.23, 95% CI: 1.25-8.36, p = 0.016). Furthermore, a high ECW/TBW was significantly associated with lower hemoglobin (p < 0.001) and albumin levels (p < 0.001), but not comorbidities.
UNASSIGNED: A high preoperative ECW/TBW was a predictive factor for recurrence and poorer overall survival independent of the tumor, node, and metastasis (TNM) stage. Our data suggest that preoperative evaluation of ECW/TBW using BIA might serve as a novel tool for developing CRC treatment strategies.

The need for a practical method for routine determination of body fat has progressed from body mass index (BMI) to bioelectrical impedance analysis (BIA) and smartphone two-dimensional imaging. We determined agreement in fat mass (FM) estimated with 50 kHz BIA and smartphone single lateral standing digital image (SLSDI) compared to dual X-ray absorptiometry (DXA) in 188 healthy adults (69 females and 119 males). BIA underestimated (p < 0.0001) FM, whereas SLSDI FM estimates were not different from DXA values. Based on limited observations that BIA overestimated fat-free mass (FFM) in obese adults, we tested the hypothesis that expansion of the extracellular water (ECW), expressed as ECW to intracellular water (ECW/ICW), results in underestimation of BIA-dependent FM. Using a general criterion of BMI > 25 kg/m2, 54 male rugby players, compared to 40 male non-rugby players, had greater (p < 0.001) BMI and FFM but less (p < 0.001) FM and ECW/ICW. BIA underestimated (p < 0.001) FM in the non-rugby men, but SLSDI and DXA FM estimates were not different in both groups. This finding is consistent with the expansion of ECW in individuals with excess body fat due to increased adipose tissue mass and its water content. Unlike SLSDI, 50 kHz BIA predictions of FM are affected by an increased ECW/ICW associated with greater adipose tissue. These findings demonstrate the validity, practicality, and convenience of smartphone SLSDI to estimate FM, seemingly not influenced by variable hydration states, for healthcare providers in clinical and field settings.

Background and Objectives: Extracellular water is increased in patients with edema, such as those with chronic heart failure, and it is difficult to assess skeletal muscle mass with the skeletal muscle mass index when extracellular water is high. We investigated the relationship between phase angle and physical function, nutritional indices, and sarcopenia in patients with cardiovascular diseases, including chronic heart failure. Methods and Study Design: In 590 patients with cardiovascular diseases (372 men), handgrip strength, gait speed, and anterior mid-thigh muscle thickness by ultrasound were measured, and the skeletal muscle mass index, phase angle, and the extracellular water: total body water ratio were measured with a bioelectrical impedance analyzer, and presence of sarcopenia was evaluated. Results: Phase angle, but not the skeletal muscle mass index, was correlated with serum albumin (r = 0.377, p < 0.001) and hemoglobin values in women. Multivariate regression analysis showed that at the extracellular water: total body water ratio below 0.4, both phase angle and skeletal muscle mass index were independent determinants of handgrip strength and log mid-thigh muscle thickness in men, after adjustment for age and presence of chronic heart failure. In contrast, for the ratio of 0.4 or greater, after adjustment for age and presence of chronic heart failure, phase angle was a stronger independent determinant of handgrip strength and log mid-thigh muscle thickness than the skeletal muscle mass index in men. Conclusions: Phase angle is a good marker of muscle wasting and malnutrition in patients with cardiovascular disease, including chronic heart failure.

Patients undergoing dialysis through a permanent catheter often experience infection or malfunction. However, few studies have clarified the predictors of permanent catheter patency survival in patients undergoing hemodialysis. We assessed the relationship between the parameters of body composition monitoring (BCM), determined before the initiation of dialysis, and the patency survival of the permanent catheters inserted in 179 patients who commenced hemodialysis between 14 January 2020 and 31 August 2021. The relationships between permanent catheter patency at 6 weeks and BCM parameters, laboratory tests, age, sex, comorbidities, and medications at baseline were studied using Kaplan-Meier survival curves. Permanent catheter patency was observed to be superior at high extracellular-to-intracellular (ECW/ICW) ratio (p < 0.005). After adjustment for covariates, the ECW/ICW ratio remained an independent factor associated with permanent catheter patency survival. When patients with non-patent catheters were subdivided into infection and malfunction groups, and the associations of BCM parameters were evaluated in those groups, the ECW/ICW ratio was not significantly associated with permanent catheter patency survival in the infection group (p = 0.327); instead, a significant association was found for the lean tissue index (p < 0.001). In the malfunction group, the ECW/ICW ratio remained significantly associated with permanent catheter patency survival (p < 0.001).